Diabetic Eye Disease

DIABETIC EYE DISEASE

Diabetic retinopathy is a complication of diabetes, caused by high blood sugar levels damaging the back of the eye (retina). It can cause blindness if left undiagnosed and untreated. However, it usually takes several years for diabetic retinopathy to reach a stage where it could threaten your sight.

To minimise the risk of this happening, people with diabetes should:

ensure they control their blood sugar levels, blood pressure and cholesterol
attend diabetic eye screening appointments – annual screening is offered to all people with diabetes aged 12 and over to pick up and treat any problems early on

HOW DIABETES CAN AFFECT THE EYES

The retina is the light-sensitive layer of cells at the back of the eye that converts light into electrical signals. The signals are sent to the brain which turns them into the images you see.

The retina needs a constant supply of blood, which it receives through a network of tiny blood vessels.

Over time, a persistently high blood sugar level can damage these blood vessels in 3 main stages:

background retinopathy – tiny bulges develop in the blood vessels, which may bleed slightly but do not usually affect your vision
pre-proliferative retinopathy – more severe and widespread changes affect the blood vessels, including more significant bleeding into the eye
proliferative retinopathy – scar tissue and new blood vessels, which are weak and bleed easily, develop on the retina; this can result in some loss of vision

However, if a problem with your eyes is picked up early, lifestyle changes and treatment can stop it getting worse.

DIABETIC RETINOPATHY

Anyone with type 1 diabetes or type 2 diabetes is potentially at risk of developing diabetic retinopathy. You’re at a greater risk if you:

have had diabetes for a long time
have a persistently high blood sugar (blood glucose) level
have high blood pressure
have high cholesterol
are pregnant
are of Asian or Afro-Caribbean background

By keeping your blood sugar, blood pressure and cholesterol levels under control, you can reduce your chances of developing diabetic retinopathy.

TYPES OF DIABETIC RETINOPATHY

There are 3 types of DR

1. Non-proliferative retinopathy

• An early stage of retinopathy with no visual symptoms associated.
• The small blood vessels of the eye swell a little.
• It is likely to be detected during annual retinal screening and should be monitored regularly.

2. Proliferative retinopathy

• Blood vessels in large areas of the retina are damaged and cause the eye to grow new blood vessels.
• These new blood vessels bleed easily, which cause a sudden shower of floaters or cobwebs in your vision. If left untreated, may cause scarring in your retina and long term visual loss.

3. Macular oedema*

• Swelling of the macular is caused by leakage of fluid from the damaged blood vessels in your eye.
• This can cause loss or distortion of central vision.

SYMPTOMS OF DIABETIC RETINOPATHY

The early stages of DR may occur without symptoms and without pain. Symptoms may only become noticeable once the disease advances.

Symptoms of retinopathy to look out for include sudden visual changes, blurred vision, and eye floaters and spots.

TREATMENT OPTIONS FOR RETINOPATHY

Strict diabetes and blood pressure control

• To reduce the risk and prevent further development of DR, it is important that your blood sugar, blood pressure and cholesterol levels are well controlled.
• Make sure to attend appointments with diabetic nurse, GP or hospital doctor regularly

Laser treatment

• Proliferative diabetic retinopathy is treated with laser.
• This treatment uses a laser to produce small areas of heat on the retina. This creates small laser burns scattered across the retina.
• The goal of laser treatment is to cause the abnormal blood vessels to shrink and disappear. It does not improve your vision but aims to prevent severe vision loss.
• Before the procedure, a local anaesthetic will be given to numb your eye as well as an eye drop to dilate the pupils.
• A special contact lens will be placed to hold your eyelids open and allow a laser beam to be focused on your retina.
• This treatment is usually not painful but you may feel sharp pricking sensation.

Surgery

• In DR, bleeding can occur in the retina and gel-like fluid fills the eye. This blood usually clears on its own. If this fails to clear, you may need surgery to remove the blood.
• In advanced DR, scar tissue can form on the retina. This causes the retina to be pulled away from the back of the eye (retinal detachment). Surgery will be required to remove the scar tissue and repair the retina.

DIABETIC MACULAR OEDEMA

Diabetic Macular Oedema (DMO) is a serious condition in which fluid builds up on the macula.

• The macula is the central part of the retina that controls our central vision, colour vision and fine detail of what we see.
• When the macula swells with fluid, central vision becomes blurry

DMO is caused by long-term exposure to high blood sugar levels caused by diabetes. The longer you have diabetes, the greater your chance of developing sight loss through DMO.

Other lifestyle factors can increase your risk of developing DMO as well such as

Smoking
Being overweight
Poor control of problems such as high blood pressure or abnormal cholesterol level

SYMPTOMS OF DMO

A person may not notice any effect on their vision in the early stages.

Dark spots like a smudge on glasses or gaps may appear in your vision (especially first thing in the morning)
Changes in shape, size or colour of objects in front of you. They may seem to move or disappear.
Colours can fade
Difficulty reading
Difficulty seeing in bright light or glare
Straight lines may appear distorted or bent

TREATMENT OPTIONS FOR DMO

Strict diabetes and blood pressure control

To reduce the risk and prevent further development of DMO, it is important that your blood sugar, blood pressure and cholesterol levels are well controlled.
Make sure to visit your diabetic nurse, GP or hospital doctor regularly.

Injections and implants

Drugs are injected into the eye to stop fluid leaking from the blood vessels and to reduce inflammation.
These are not as bad as they might sound. Your eye will be numbed by an eye drop and you should feel no more than a little pressure during the procedure.
The drugs most commonly used are anti-VEGF agents: Aflibercept ( Eylea), Ranibizumab ( lucentis), and Faricimab ( Vabysmo) which is an anti-VEGF and and an Anti- ANG-2.
This treatment cannot restore sight if there is already significant damage to the macula.
Your eye doctor will discuss which injections or implants is most suitable for you.

Laser Treatment

Some people may be offered laser treatment when the
DMO does not involve the centre of the macula.
This treatment aims to stabilise vision and does not aim to improve sight.
Before the procedure, a local anaesthetic will be given to numb your eye as well as an eye drop to dilate the pupils.
A special contact lens will be placed to hold your eyelids open and allow a laser beam to be focused on your retina.
This treatment is usually not painful but you may feel sharp pricking sensation